Resister



H.H.JOHNSTON. RESISTER.

APPLlCATlON FILED IAN. 8. I919.

' 1,387,492. Patented Aug. 16,1921.

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HARVEY H. JOHNSTON, OF,ED,GEWOOD PARK, PENNSYLVANIA, ASSIGNOR 'IO XVEST- INGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVTAN IA.

RESISTER.

I Specification of Letters'Patent.

Patented Aug. 16 1921.

Application Med January 8, 1919. Serial :No. 270,144.

To all whom' it may concern:

Beitknown that I, .I'IARVEY H.JOHNSTON, a citizen of the United States, and a resident of Edgewood Park, in the county of Allegheny and Stateof Pennsylvania, have in vented a new and useful Improvement in Resistors, of which the following is a specification.

My invention relates to resisters of the type usually employed on railway vehicles and it has particular relationto the pressed metal-grid type of such apparatus.

The object of my invention is to provide apparatus of the character designated in which the number of contact surfaces is r educed, the structure simplified and I111? proved and the manufacturingcost reduced.

In the accompanying drawings, Figure 1 is a side elevational view of a resistor constructed in accordance with my invention; Fig. 2 is a bottom plan view thereof, and Fig. 3 is a side view, partially in section and partially in elevation, of the device shown in Fig. 1. I

Heretofore, it has been customary in the manufacture of resistors of this type to mount a number of resistance grids upon insulated tie rods and to separate them by means of alternately disposed conducting and insulating spacer members, usually mounted on the tie rods. An objection to this type of construction is that there is a large number of parts, which adds to the cost of assembly, and also there is a large number of contact surfaces which, together with the fact that there is usually nothing to hold the various parts together, in the event that the nuts at the end of the tie rod become loosened, renders this a serious objection to this type of resister. Foreign matter of an insulating nature may get interposed be tween two members which should be held in close engagement with each other, resulting in an open circuit in the resistance.

By my invention, I provide portions integral with the grid member and bent back upon themselves adjacent to the tie rods, forming spacing members between the grids and electrical contacts between the grids at alternate ends of the resistance member. By this structure, the numberof contacts is reduced 50%, and the number of separate parts approximately 25%. Any looseness in the grid members upon the tie rods is taken up by the tendency of the bent-over portionsto spread apart, thus insuring good electrical contactat all times.

For a further understandiugof my invention, reference may now be had to the accompanying drawings in which I show a plurality of gridmembers' 1 provided with integral bent-over portions 2, which constitute spacing members, and mounted upon transversely extending rods 3 which are provided with an insulating covering l. Intermediate the alternate ends of the grids mounted on each tie rod are disposed insulating spacer members 5. The tie rods 3 extend through openings 6 in-the grid member 1 and also in thebent-over portion 2 which I show as circular openingsihut whichcould as well be slots or any other form of openings.

This type of resister is very desirable, from a manufacturing point of view, since the entire resistor, including the bent-over spacing portion 2, may be punched from a single piece of pressed metal. After the portion 2 is bent into position the grid is ready for mounting. Also, the spacing portions 2-, being bent over, have a tendency to stand out from the main body of the grid member and this feature of resiliency is advantageous, since the various members would I be held in close engagement with each other,

even though the nuts (not shown) on the end of'the rod 3 should loosen.

From the foregoing description, it will be obvious to those skilled in the art that I have provided a resistor employing a minimum number of separate parts in which there is but one contact per grid per connection to adjacent grid and which is strong and durable in operation and simple and inexpensive to manufacture.

While I have shown but one form of my invention, I desire it to be understood that it is not so limited but is susceptible of various minor changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or are specifically set forth in 2. An electrical resister comprising a grid having a main body portion and having, also, a spacing port-ion adjacent to the end thereof bent back upon itself.

3. An electrical resister consisting of a plurality of grids in side-by-side relation, and spacing means disposed intermeciate ad jacent grids comprising portions of said grids bent back upon themselves.

4. An electrical resister consisting of a plurality of grids in side-by-side relation and attached together by means of tie rods transverse thereto, and means for spacing adjacent grids apart comprising portions of said grid members bent back upon themselves.

5. in electrical resister consisting of a plurality of grids in side-by-side relation and attached together by means of tie rods transverse thereto, and means for spacing adjacent grids apart on said tie rods comprising portions of said grids adjacent said tie rods bent back upon themselves.

6. An electrical resister consisting of a plurality of grid members attached together by means of tie rods, and means for spacing said grid members apart, said means comprising portions of said grid members adj acent said tie rods bent back upon themselves and openings through said grid members and 30 said bent back portions to receive said tie rods.

7. An electrical resister comprising a plurality of punched metal grid members mounted in stacked relation, each of said grid members having a portion thereof bent back upon itself to form an electrical connection between adjacent grid members and insulating spacing members disposed intermediate alternate grid members.

8. An electrical resister comprising a plurality of punched metal grid members mounted in spaced relation on insulating tie rods, spacing means comprising portions of said grid members bent back upon themselves, said grid members and said bent back portions being provided with openings through which said tie rods extend, and additional insulating spacing means mounted on said tie rods intermediate alternate grids.

In testimony whereof, I have hereunto subscribed my name this 24th day of Dec. 1918.

HARVEY H. JOHNSTON It is hereby certified'that in Letters Patent No. 1,387,492, granted August 16,

I 1921, upon the application of Harvey H. Johnston, of Edgewood Park, Pennsylnia, for an improvement in Resisters, errors appear in the printed specification requiring correction as follows: Page 2, line 15, claim 4, for the words grid members read grids; same page line 21, claim 5, strike out the word apart; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 4th day of October, A. D., 1921.

[SEAL] KARL FENNING,

Acting Commissioner of Patents.

(inflections 'm'Letters Patent No,

It is hereby certified'that in Letters Patent N 0. 1,387,492, granted August 16, 1921, upon the application of Harvey H. Johnston, of Edgewood Park, Pennsylrania, for an improvement in Re sisters, errors appear in the printed specification requiring correction as follows: Page 2, line 15, claim 4, for the words grid members read grids; same page line 21, claim 5, strike out the Word apart; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 4th day of October, A. D., 1921.

KARL FENNING,

Acting Commissioner of Patents. 

